When would you use surface area?

Answer 1

You use surface area whenever you want to know the area of a non-flat surface. This is useful in a lot of physical applications. For example, heat flow, electrical current flow, or fluid flow through an irregularly-shaped region all are defined in terms of integrals over the boundary, and integration is taken with respect to surface area.

Answer 2

Surface area is used to calculate the amount of material required to cover or coat an object, such as paint or wallpaper. It is also used in heat transfer calculations, such as determining the rate at which heat is exchanged between an object and its surroundings. Additionally, surface area is used in geometry to calculate the size and shape of 2D and 3D objects.